Hi, just share the gapps here...
Thanks, for those. As I had gapps before, these were needed to get the ROM to boot.
I was using TWRP. I updated from the previous version of this ROM (Lineageos 17.1).
In TWRP -> Install -> Choose the Rom.zip. (I wiped dalvik and cache, but I am not sure if that is needed). Go back. Install -> gapps.zip -> Reboot.
I had the same problem as mentioned in 2. by @Micropod. To remove the lock I followed:
Recently when i restored my data using TWRP i faced a problem at lock screen. I was not able to unlock my phone with the pin i set Earlier..So after so many attempts i was able to find a solution for that problem.(works with pattern,pin etc)...